PORT ANGELES — After four years of filming, editing, testing and re-editing, a documentary of the restoration of the Elwha River is ready for prime time — but not before a test screening in front of the Port Angeles public.

“Return of the River” will be shown at 7 p.m. Thursday at Peninsula College's Little Theater, 1502 E. Lauridsen Blvd.

Admission is free. Space will be limited to available seating. Donations to help offset the cost of the film will be accepted.

The film documents the history of the Elwha River, the decades-long efforts to remove the Elwha and Glines Canyon dams, and the restoration efforts to bring salmon runs back to the southern 70 miles of the river.

“It's still a divided story. Some people still wish the dams were still there,” said John Gussman, a filmmaker from Sequim who has been working on the film for four years.

The Elwha River, a 45-mile salmon-producing river with several major salmon-producing tributaries that added up to a total of 77 miles of salmon habitat, was dammed by Elwha Dam 5 miles from its mouth in 1912 to provide electricity to the emerging city of Port Angeles.

A second dam, the 210-foot Glines Canyon Dam, was built 8 miles upstream from Elwha Dam in 1927.

Both dams were built without fish ladders — required by law at the time they were built — which virtually eliminated salmon from most of the river.

In 2010, Gussman began filming the river and dams in preparation for the $325 million dam removal project, the largest in U.S. history, that began in September 2011, and he contacted people who were part of the process.

Jessica Plumb of Port Townsend joined the effort 2½ years ago as co-director, producer, editor, and writer.

“It's a total labor of love for the two of us,” Plumb said.

Gussman and Plumb have interviewed dozens of activists, dam workers, scientists, Olympic National Park officials and members of the Lower Elwha Klallam tribe.

They researched the history of the river and spent hundreds of hours on the river itself, filming the processes of change, including explosive blasts, as the dams were removed.

They also were on hand to film some of the first salmon to swim past the former Elwha Dam site in 2012.

The $75,000 film has been funded through crowd sourcing and from donations of time and equipment by the filmmakers.

“We did it on a shoestring,” Gussman said.

Plumb said each of the co-producers had a different skill to contribute to the film.

“John was the eyes, and I was the voice,” she said.

Gussman and Plumb have applied to enter the film into many small film festivals and two major festivals: the Telluride Film Festival, Aug. 29 to Sept. 1 in Telluride, Colo.; and the Toronto International Film Festival, Sept. 4-14 in Toronto.

The large festivals require that films submitted must be premiere showings, so the DVD and Internet streaming versions will not be released until after the two know whether the film was accepted for one or both festivals, Gussman said.

If the film is not selected for either of the major festivals, it will be released to the public as soon as the filmmakers are notified.

If it was selected for a major festival, the release will be delayed until after the festivals are over, he said.

It has been selected for the Port Townsend Film Festival, Sept. 19-21, the Kuala Lumpur Eco Film Festival, Oct. 17-19, in Malaysia and the Friday Harbor Film Festival, Nov. 7-9.

There will also be an Oct. 22 showing in Port Angeles, Gussman said.

He said he also has hopes the film will be picked up for broadcast.

Gussman and Plumb have shown working versions of the film — 20 or 30 minutes — to North Olympic Peninsula audiences for feedback as the film developed and made changes as needed.

While the film is the final cut before its official release, new material may be added as the river continues to change and evolve, Gussman said.

“It is probably not final, ever,” he said.

Elwha Dam was demolished by March 2012. Glines Canyon Dam still has about 30 feet of dam “apron” to be removed.

Efforts to re-establish salmon populations and to replant the emptied lakebeds are ongoing.